Role of Nitrogen in Suppressing Interfacial States Generation and Improving Endurance in Ferroelectric Field-Effect Transistors

In this study, we investigate the impact of nitridation in Hf $_{{0}.{5}}$ Zr $_{{0}.{5}}$ O2-based ferroelectric field-effect transistors (FeFETs) with a SiON interfacial layer (IL). We fabricated the SiON IL using decoupled plasma nitridation. Compared with the SiOx interlayer, the SiON interlayer can reduce interfacial state density (D $_{\text {it}}\text {)}$ at the interlayer/Si interface, suppress the degradation of Ion and subthreshold swing (SS), and improve endurance under the same electric field across the IL. The physical origin is that the nitridation can reduce trap generation rates at both the Hf $_{{0}.{5}}$ Zr $_{{0}.{5}}$ O2/interlayer and interlayer/Si interfaces.